Innovative superheated steam impingement blanching(SSIB)enhances drying rate and quality attributes of line pepper

Blanching is an essential step before processing of agricultural products as it can inactivate enzymes that cause undesirable changes.In current work the effects of superheated steam impingement blanching(SSIB)time and temperature on drying characteristics and red pigments content of line pepper were investigated.Results showed that after a 3-min SSIB pretreatment at 110℃ the pepper epidermis covered with wax coat was damaged.In addition,the drying time was extensively decreased and the loss of red pigments of dried products was reduced.Results showed that the whole drying process took place in the falling rate period,which indicated that diffusion was the dominant physical mechanism governing moisture movement in the samples.Therefore,the second Fick’s law of diffusion was used to determine the effective moisture diffusivity(Deff)of line pepper,which increased from 1.193×10^-10 to 3.128×10^-10 m^2/s with increasing of the drying temperature and air velocity.The drying activation energy(Ea)of pretreated samples was 34.31 kJ/mol,which decreased by 3% compared with the non-pretreatment group.The findings of this work indicate that SSIB is very promising pretreatment technique as it not only enhances drying process but also improves bioactive substance preservation of red pepper.

高温高湿气体冲击处理对中短波红外干制红枣品质的影响

为提高干制枣果品质,将高温高湿气体冲击处理技术应用于红枣中短波红外干燥前处理中,探究其对不同中短波红外干燥温度下枣果的主要酚类物质、维生素C、可溶性糖、三萜酸、环磷酸腺苷、总酚、总黄酮含量及抗氧化活性的影响,研究结果表明:不同处理及干燥温度下干制枣果共鉴定出8种酚类物质、4种可溶性糖、4种三萜酸,其中儿茶素、绿原酸为主要的酚类物质,蔗糖为主要的可溶性糖,白桦脂酸为主要的三萜酸。枣果经高温高湿气体冲击处理后中短波红外干制与未处理对照组相比其主要酚类物质、可溶性糖、三萜酸、维生素C、总酚、总黄酮、环磷酸腺苷含量较高且抗氧化活性较强,表明高温高湿气体冲击处理技术是一种优良的红枣干燥前处理方法。